An interesting case of spontaneous inversion of the left atrial appendage was caused by an acute decrease in ventricular volume and the shortening of diastole during supraventricular tachycardia, creating a negative pressure invaginating the left atrial appendage. The return of normal in sinus rhythm and left-sided diastolic pressures reversed the ...

Atrial fibrillation (AF) induces a progressive dilatation of the atria which in turn might promote the arrhythmia. The mechanism of atrial dilatation during AF is not known. To test the hypothesis that loss of atrial contractile function is a primary cause of atrial dilatation during the first days of AF, ...

A large hiatal hernia constitutes a form of posterior mediastinal mass that can encroach on the posterior aspects of the heart. During two-dimensional echocardiography this phenomenon may be confused with an intra-atrial mass or various other posterior mediastinal masses. Furthermore, such a large hiatal hernia encroaching on the heart may ...

We hypothesized that caloric restriction (CR)-induced hypotension would correlate with increased sodium excretion through an atrial natriuretic peptide (ANP)-dependent mechanism. To test this hypothesis, the cardiovascular parameters of c57/Bl mice were measured with radiotelemetry while urine was collected. The 23-h mean blood pressure (BP) dropped from 108.6 +/- 1.8 to ...

Blockade of AngII (angiotensin II) and ET (endothelin)-1, established and potential therapeutic strategies respectively, for heart failure, may have an adverse effect on the cardiac secretion of the natriuretic peptides, hormones with actions beneficial in this disease. The present study investigates the roles of AngII and ET-1 in regulating the ...

BACKGROUND: Early transmitral velocity/tissue Doppler mitral annular early diastolic velocity (E/Ea) and B-type natriuretic peptide (BNP) have been correlated with left ventricular filling pressures, yet there are no data on how these 2 estimates of left ventricular filling pressures compare. METHODS AND RESULTS: Patients admitted to intensive care underwent simultaneous ...

Irregularity of ventricular cycles is a cause of haemodynamic impairment and symptoms in patients with atrial fibrillation (AF). AIM OF THE STUDY: Aim of the study was to determine the optimal pacing rate to stabilise ventricular cycle length at rest in patients with chronic AF, bradycardiac symptoms and VVI pacing. ...

Greater change of postural blood pressure (BP) is often seen in elderly hypertensives and is recognized as a risk factor for cognitive decline and poorer cerebrovascular outcome, but its clinical significance still remains to be clarified. We performed a head-up tilting test, ambulatory BP monitoring, and brain MRI in 59 ...

BACKGROUND: Brain natriuretic peptide (BNP) is a cardiac hormone with vasodilating, natriuretic, renin-angiotensin-aldosterone-inhibiting and lusitropic properties. We have demonstrated that acute subcutaneous (SQ) administration of BNP in experimental congestive heart failure results in elevation of plasma BNP and its second messenger 3',5'-cyclic guanosine monophosphate (cGMP) with natriuresis and reduction in ...

BACKGROUND: Chronic atrial stretch and rheumatic inflammatory activity leads to atrial dilatation and conduction slowing, and this increases the susceptibility to atrial fibrillation (AF). The aim of this study was to examine the effects of changes in the chronic atrial stretch on atrial refractoriness in the early period after percutaneous ...

To evaluate the acute effects on haemodynamic variables of biatrial pacing in comparison with high right atrial (HRA) pacing and left lateral atrial pacing. 23 patients were paced from the HRA site, the lateral site of the coronary sinus (CS), and both sites on two fixed atrioventricular delays (100 and ...

OBJECTIVE: Estrogen replacement therapy (ERT) has been reported to affect blood pressure. Since natriuretic peptides have natriuretic and vasodilatory activity and also inhibit the renin-angiotensin-aldosterone system and lower blood pressure, it was hypothesized that the changes in blood pressure effected by ERT might be mediated via changes in natriuretic peptides. ...

BACKGROUND: Vasoactive peptides are accepted indicators of the degree of heart failure and its progression or improvement following medical therapy. Normalization of cardiac hemodynamics by cardiac transplantation (HTx) may lead to normalization of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) plasma levels shortly after the procedure. METHODS: Long-term ...

BACKGROUND: Atrial fibrillation (AF) is the most common tachyarrhythmia encountered by clinicians. When AF occurs in patients with structural disorders, hypertension is most common. Hypertension may provoke or enable AF to occur through several mechanisms. One could be the resultant effects of increased afterload on the left ventricle and consequent ...

BACKGROUND: Increased plasma endothelin (ET)-1 concentrations have been observed in patients with rheumatic mitral stenosis (MS). However, the mechanisms of increased circulating ET-1 in patients with MS remain unclear. METHODS: We measured plasma concentrations of ET-1 in blood samples from the femoral vein and artery, and right and left atria ...

OBJECTIVES: The role of atrial myocytes and extracellular matrix (ECM) changes in atrial chamber remodeling was studied in a canine model of heart failure (HF). BACKGROUND: Cardiac remodeling is a key process mediating the progression of HF. Studies of the structural mechanisms of cardiac remodeling have been limited to the ...

Global myocardial index (GMI) has been significantly related to left ventricular filling pressure. We hypothesized that GMI and echographic indicators of atrial dilatation were significantly different in pAF pts compared to normals. METHODS: 39 patients (pts) without structural heart disease, aged 52+/-10 years with pAF were compared to 36 control-matched ...

BACKGROUND: The prevalence of inflammation is high among patients with chronic renal failure but the reason of inflammation is unclear. We test the hypothesis that inflammation in chronic renal failure could be the consequence of an increased left-ventricular wall tension related to ventricular dysfunction, hypervolemia or both. METHODS: For assessing ...

BACKGROUND: A wide range of left atrial pressures exist in rheumatic mitral stenosis despite similar mitral valve area. Left atrial compliance may be an important determinant of left atrial pressure in mitral stenosis. Data regarding left atrial compliance in rheumatic mitral stenosis and changes following balloon mitral valvotomy are scarce. ...

AIMS: Assess the value of peak atrial systolic mitral annular velocity (Aann) measured by Doppler tissue echocardiography to quantify left atrial systolic function. METHODS: We studied a total of 61 adults; 10 subjects without history of heart disease and 51 patients with a history of atrial fibrillation or undergoing evaluation ...

The aim of this study was to evaluate the effectiveness of an angiotensin-converting enzyne inhibitor (ACEI, quinapril) or angiotensin II receptor blocker (ARB, candesartan) on atrial natriuretic peptide (ANP) activity in rats with hypertension induced by nitric oxide (NO) inhibition. ACEI and ARB have a number of pharmacologic effects, including ...

The relative roles of neural and pressure gradient factors, causing a fall or maintenance of bronchial blood flow in exercising sheep, are unknown. These were examined in sheep prepared under thiopentone/isoflurane general anaesthesia with a pulsed Doppler probe mounted on the bronchial artery, and aortic pressure (Pa) catheter in superficial ...

B-type natriuretic peptide (BNP) has been proven to be a biochemical marker of severity of congestive heart failure. We are aware of only few papers reporting the association of BNP elevation and pulmonary hypertension (primary, thromboembolic, or as a consequence of chronic obstructive pulmonary disease). Less is known about BNP ...

Cardiac hypertrophy is an early landmark during the clinical course of heart failure, and is an important risk factor for subsequent morbidity and mortality. The hypertrophy response to different types of cardiac overload is distinguished both at the molecular and cellular levels. These changes have been extensively characterized for pressure ...

OBJECTIVE: To evaluate the effects of scorpion venom and antivenom in experimental envenomation. DESIGN: Prospective, controlled animal study. SETTING: University research laboratory SUBJECTS: Twenty-nine anesthetized and ventilated dogs. INTERVENTIONS: The first group of animals had venom alone (0.05 mg/kg). Animals from the second group had simultaneous administration of 10 ml ...

Brain natriuretic peptide (BNP), a neurohormone secreted from the ventricular myocardium in response to hemodynamic load/wall stress, in congestive heart failure (CHF). This study was performed to evaluate the correlation between BNP level and clinical presentations and hemodynamic parameters obtained by echo-Doppler (echo-Doppler) analysis, and its relation with disease severity ...

OBJECTIVE: To date, the contribution of basal atrial natriuretic peptide (ANP) levels to resting vascular function in humans is unknown. In the present study we sought to investigate the role of ANP in regulating regional vascular volume and venous tone in healthy subjects. METHODS AND RESULTS: We used radionuclide plethysmography ...

BACKGROUND: Atrial natriuretic peptide (ANP) has vasodilating and diuretic/natriuretic properties, both of which contribute to lower blood pressure. These effects are mediated by binding of ANP to a cell-surface receptor [type A guanylyl cyclase (GC-A)]. It has been demonstrated by studies in monogenetic mouse models that the ANP/GC-A system participates ...

Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are cardiac hormones, secreted by the atria and ventricles, respectively, in the normal adult heart. They participate in the regulation of blood pressure and body fluid homeostasis and modify growth and development of cardiovascular tissues and bone. Levels of ANP are ...

BACKGROUND: There is little information available concerning plasma concentrations of B-type natriuretic peptide (BNP) in children with a ventricular septal defect. The aim of the present study was to determine hemodynamic factors that control plasma concentrations of BNP and the clinical implications of BNP compared with atrial natriuretic peptide (ANP) ...

There are very limited data on the effects of bundle branch block (BBB) in patients with atrioventricular nodal reentrant tachycardia (AVNRT). Studies in a total of 155 patients with 162 episodes of AVNRT were retrospectively analyzed. A total of 38 patients (25%) developed spontaneous right BBB, whereas 5 (3%) developed ...

Cardiac hypertrophy is a common and often lethal complication of arterial hypertension. Atrial natriuretic peptide (ANP) has been postulated to exert local antihypertrophic effects in the heart. Thus, a loss of function of the ANP receptor guanylyl cyclase-A (GC-A) might contribute to the increased propensity to cardiac hypertrophy, although a ...

Although expression of natriuretic peptides in cardiac tissues is up-regulated in response to pressure overload, no significant change in cGMP level in hypertrophied ventricles was observed. Activities of two cyclic nucleotide phosphodiesterase (PDE) isoforms, Ca2+/calmodulin-stimulated PDE (PDE1) and cGMP-stimulated PDE (PDE2), were significantly higher in rat left ventricles 14 days ...

The aim of this prospective study was to investigate, using echocardiography, the relationship between heart murmurs found in the neonatal period and atrial septal defect (ASD). Heart murmurs were detected in 115 of 5124 term neonates within 1 month after birth. The babies were followed by echocardiographic examination with attention ...

The role of atrial lead location in cardiovascular function in the presence of impaired ventricular dysfunction is unknown. We tested the hypothesis that left atrial (LA) and left ventricular (LV) hemodynamics are affected by alterations in AV delay and are influenced by atrial pacing site in dogs with dilated cardiomyopathy. ...

BACKGROUND: Left atrial pressure (LAP) monitoring provides a useful option for management of hemodynamic status in pediatric open-heart surgical patients during the postoperative period. PATIENTS AND METHOD: We used a triple-lumen catheter placed into the left atrium transseptally to measure left atrial pressure. Twenty children that were operated on in ...

BACKGROUND: Pulmonary capillary wedge pressure (PCWP) is a useful index of preload and an important determinant of cardiac function. HYPOTHESIS: We postulated that the rate of blood propagating into the left atrium (LAIF-PR) would be a useful measure of PCWP in critically ill patients. METHODS: Fifty-two critically ill patients (36 ...

The morphogenesis of most types of human congenital cardiac malformations is still obscure. The reasons for this are, first, the paucity of data from human embryos and fetuses and, second, the paucity of appropriate animal models. During the past few years, we have tested several chemicals for their teratogenic potential, ...

BACKGROUND: The mechanisms of the atrial contractile dysfunction induced by atrial fibrillation (AF) are not completely understood. In particular, the relation between the atrial dysfunction and electrical remodeling has not yet been studied. METHODS AND RESULTS: Seven goats were chronically instrumented with electrodes sutured to the atria and with ultrasonic ...

INTRODUCTION: Atrial dilation plays an important role in the development and persistence of atrial fibrillation (AF). The mechanisms by which atrial dilation increases the vulnerability to AF are not fully understood. METHODS AND RESULTS: In 11 isolated rabbit hearts, the right atrium was acutely dilated by increasing the intra-atrial pressure ...

INTRODUCTION: Atrial dilatation may play an important role in the occurrence of atrial fibrillation (AF) in clinical situations. However, the electrophysiologic characteristics of dilated atria are still unclear. METHODS AND RESULTS: In 18 isolated Langendorff-perfused canine hearts (14.6 +/- 2.2 kg), we measured atrial effective refractory periods (ERPs) at four ...